On Nov 17, 2007 5:12 AM, Bob Metelsky bobmetelsky@comcast.net wrote:

Im a dba not a network guy... :) Well.... ok I know there are technical "reasons" why this doesn't seem to "work"

But - why can I ping any other ip address .... ie Google 64.233.167.99

Because the routes, ( C:> route print ) say to send such packet to your GW, that know nothing about 10.54.0.0/24 and then follow its own route to is own GW that do the same ... Finlay nobody on the internet know about 10.54.0.0/24 and you never get answered. But Internet know about Google, that get the packet and answer.

If you teach your GW or your own computer for what to do with such packets, they will reach their target AND if the reverse way is well defined too you will get an answere.

Ok I guess thats "resolvable" and not private. My thinking is ping should try and "find" the address

Maybe I need a type of local dns...(??) How does one avoid manually adding "routes"

No way, DNS don't configure route, you cannot break away

my port scanner - I give a range 10.54.0.0 - 10.54.7.55, Im thinking it should try all addresses in between and it only gets the ones on 10.54.7.0

The comment below sounds like what I need... thanks!

" c:> route add 10.54.0.0 MASK 255.255.255.0 10.54.7.16

But this should give you access on both 10.54.0.2 and 10.54.0.3 "

C:>route add 10.54.0.0 MASK 255.255.255.0 10.54.7.16

C:>ping 10.54.0.2

Pinging 10.54.0.2 with 32 bytes of data:

Reply from 10.54.0.2: bytes=32 time<1ms TTL=64 Reply from 10.54.0.2: bytes=32 time<1ms TTL=64

My purpose is to have a private network between database servers (oracle rac) where only specific traffic is allowed, and it works that way, I was just surprised that I want able to ping the 0 subnet.

Dont forget IP protocol and ETHERNET protocol are working together here. You should know how.

So I need to add the route...

Thanks for everyones feedback. Hopefully I can contribute something....in the future ;-)

Regards.

Bob

Alain Spineux wrote: On Nov 17, 2007 1:25 AM, Bob Metelsky bobmetelsky@comcast.net wrote:

Hi Im a little perplexed by this situation

I have centos 4.5 installed on 2 pcs - each with 2 network cards

machine 1

eth0 Link encap:Ethernet HWaddr 00:14:2A:6B:C8:CC inet addr:10.54.7.2 Bcast:10.54.7.255 Mask:255.255.255.0

eth1 Link encap:Ethernet HWaddr 00:11:50:9B:A2:90 inet addr:10.54.0.2 Bcast:10.54.0.255 Mask:255.255.255.0

machine 2

eth0 Link encap:Ethernet HWaddr 00:14:2A:69:4C:47 inet addr:10.54.7.3 Bcast:10.54.7.255 Mask:255.255.255.0

eth1 Link encap:Ethernet HWaddr 00:11:50:9B:A5:0A inet addr:10.54.0.3 Bcast:10.54.0.255 Mask:255.255.255.0

machine 1 & 2 can ping each other on either subnets

machine 3 (windows)...

C:>ipconfig

Connection-specific DNS Suffix . : IP Address. . . . . . . . . . . . : 10.54.7.16 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 10.54.7.1

cant ping anything on the 10.54.0 subnet, nor does that subnet show up ip using a port scanner...

C:>ping 10.54.0.2

Pinging 10.54.0.2 with 32 bytes of data: Request timed out. Request timed out.

C:>ping 10.54.7.2

Pinging 10.54.7.2 with 32 bytes of data: Reply from 10.54.7.2: bytes=32 time<1ms TTL=64 Reply from 10.54.7.2: bytes=32 time<1ms TTL=64

Any ideas why this is happening? I dont have a firewall on the 10.54 address,

Yes ! You have to learn how works IP networks :-) IP is wild and wide :-)

you can try this on your windows :

c:> route add 10.54.0.2 MASK 255.255.255.255 10.54.7.2

OR

do the same on your router at 10.54.7.1

OR (depend on how your linux box is configured)

c:> route add 10.54.0.0 MASK 255.255.255.0 10.54.7.16

But this should give you access on both 10.54.0.2 and 10.54.0.3

OR if routing is enable on 10.54.7.2

c:> route add 10.54.0.0 MASK 255.255.255.0 10.54.7.2

should also give you access to both 10.54.0.2 and 10.54.0.3

You just have to understand the first one other are just to spread out my IP knowledges. Ops, the last one is sometime useful to configure a device on another IP range, without reconfiguring your IP. Like when unpacking a new router with IP 192.168.123.1

Regards.

Thanks Bob

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...

Any ideas why this is happening? I dont have a firewall on the 10.54 address,

presumably, the windows machine is connected to the 'eth0' network that the centos machines are connected to?

how exactly do you expect the packets to get from there to the other network? the windows machine has been instructed to forward all unknown packets to 10.54.7.1, which presumably is some other sort of router... chances are, said 10.54.7.1 has no clue where 10.54.0.xxx is.

Ya- I see - your right the router is 10.54.7.1 The rest of the network switches are hubs off of that (all still 10.54.7.)

this private network is truly private (independent to the 2 computers connected) in other words they are off the network, their traffic oesn't go through a switch.

I didn't give this enough thought ....

the fact is I dont need to connect to the 0 address directly from the windows machine. The 0 address is only for private network between the database servers...

I was just curious that I couldn't ping them, I thought ping (and the port scanner) should magically find them (like dns) ...

solution 1) configure a linux computer to do 'ip forwarding', and give the windows machine a route like...

C> route add 10.54.0.0 mask 255.255.255.0 gw 10.54.7.2

or, solution 2) configure the router at 10.54.7.1 to have a route to this other network.

if both networks are on the same hub/switch, then I can only ask... WHY?

Thanks for the insight,

Bob